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Monday, March 16, 2009

Emperor Penguin Couples Stay Near Each Other in a Crowd

Breeding Penguin Couples Stay Close in a Crowd By HENRY FOUNTAINPublished: March 16, 2009

Breeding pairs of emperor penguins have a problem. They don’t have breeding territories, so they defend their partnership by staying together until the female lays its egg and transfers it to the male (who will incubate it, alone, for several months). This defense extends to their vocalizing — they remain silent until the egg is laid, so that an unpaired penguin can’t disrupt them.

Yet to keep warm and conserve energy during mating season, emperors must huddle with hundreds of other birds. Huddles form for a few hours, break up for a while and re-form again with different birds, over and over during the Antarctic winter. It’s the penguin equivalent of a mosh pit.

So how does a silent pair of emperors avoid becoming separated amid all the confusion? The answer, according to a study in The Proceedings of the Royal Society B: Biological Sciences, is that they stick close by each other in the crowd.

André Ancel of the Hubert Curien Multidisciplinary Institute in Strasbourg, France, and colleagues attached data loggers to four breeding pairs in a colony of 3,000 emperors near Dumont d’Urville Station. The devices recorded when temperatures rose and light intensity decreased, evidence that the penguins were huddling.

The researchers found that both members of a pair participated in the same huddle 84 percent of the time, with one penguin entering or leaving the huddle within a few minutes of the other. That suggests that the mates kept in physical, or at least visual, contact almost all of the time.

Story courtesy of the NY Timeshttp://www.nytimes.com/2009/03/17/science/17obhuddle.html?_r=1

Image courtesy of Flickr

Full paper for basis of report at:http://rspb.royalsocietypublishing.org/content/early/2009/03/06/rspb.2009.0140.abstract